For more than four decades, children have played with toy miniature building sets, for example a building set known as Lincoln Logs, where miniature, log-simulating units with notched grooves are mated with one another to build structurally sound toy houses, stockades, bird houses and other small structures. As the small, generally cylindrical Lincoln Logs are held in position relative to each other by the coaction of grooves at the ends of each log, the structure built by the child can be readily assembled and disassembled without the use of adhesives or other fastening devices. Such toy building sets have served their function well and provided many hours of pleasant and rewarding activities for children.
U.S. Pat. No. 5,846,114 discloses a building unit for constructing a structure, the unit being in the shape of a generally cylindrical log formed by a light-weight, resilient core encased snugly in a fabric covering having the same shape as the core. The invention discloses the use of the above units to build an interconnecting structure which can house children or adults and which be used for many purposes other than a toy house.
U.S. Pat. No. 5,145,440 is directed toward a toy house that is of a size that can actually be occupied by a child. In this invention, the play structure is constructed of inflatable elements that are deflated when not in use and stored in a relatively deflated condition.
U.S. Pat. No. 3,257,762 is directed to the same basic structure as the Lincoln Log play house but which may actually be used as such for construction of more structurally stable buildings by adults. Each building unit of each structure is inwardly tapered in width at the top and bottom thereof to facilitate assembly of the joints. The shape and configuration of the notches and recesses distinguish this invention from other building units. The building unit, according to the invention, when driven together to form an interlocking joint, are impacted together to an extent where the area of impact is considerably greater than that occurring in prior art joints.
U.S. Pat. No. 2,059,588 discloses building units comprising simulated log members substantially square in cross-section with notches in their faces adapted to interfit when the logs are arranged in cross relationship so as to permit the body of each log in each wall portion to have flat face arrangement with the body of an adjacent log in the same wall portion. Short simulated log members comprise rectangular cross-section members having notches in substantially centered positions longitudinally and adapted to have interfitting engagement with the ends of the first mentioned logs at a wall opening such as a doorway.
U.S. Pat. No. 1,936,571 discloses a simulated log structure specifically for building a toy house that may be used as a bird house. The toy house comprises a base floor, walls on the base floor formed by a series of elongated wall units and keying units between the wall units, a roof covering the walls, fastening rods carried by the base floor and extending upwardly through the walls at the corners of the house, and a nut threaded upon the upper end of each rod for clamping the roof and wall elements in assembled relation upon the base floor. The wall units or building blocks provide log simulating units and preferably have their outer surfaces rounded, and have flat upper and lower and inner faces.
While the prior art recognizes the use of generally cylindrical logs, the present invention is directed to a substantially cylindrical-shaped log which has two planar surfaces substantially perpendicular to each other formed on the surface of the log with the remaining surface being generally cylindrical to provide structural support which is superior to that of a building log unit with only a cylindrical surface. It is also another object of the invention to provide a building log unit which provides the child an option of the interior and exterior play surface and which further selectively provides a traditional exterior of round logs as well as a more modern exterior of a substantially planar surface, as well as providing a log structure which has excellent stability and structural strength when used as a base log, as well as a log placed in a intermediate position in a structure.